From Webyog Softworks:
Visifire for Silverlight gives you a set of open source data visualization components that are powered by Microsoft Silverlight and WPF. With Visifire you can create and embed visually stunning animated Silverlight Charts within minutes. Visifire is easy to use and independent of the server side technology. It can be used with ASP, ASP.Net, PHP, JSP, ColdFusion, and Ruby on Rails or just simple HTML.